Intermittent shutting off while driving and not restarting

Hi,

If it starts with starting fluid, it sounds like the fuel pump is bad. What I suggest at this point is to check fuel pump pressure to confirm it is within the manufacturer's specs. Here is a link that shows in general how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the directions specific to your vehicle. The specs / pressures are included in the directions. Also, the pics correlate with the directions.

___________________________

1998 Mitsubishi Truck Montero Sport LS 2WD V6-3.0L SOHC
Component Tests and General Diagnostics
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
FUEL PRESSURE TEST

Required Special Tools:
- MB991502: Scan Tool (MUT-II)
- MD998709: Adaptor Hose
- MD998742: Hose Adaptor

1. Release residual pressure from the fuel line to prevent fuel spray.

WARNING: To prevent a fire, cover the hose connection with shop towels to prevent splash of fuel that could be caused by some residual pressure in the fuel pipe line.

pic 1

2. Disconnect the high-pressure fuel hose at the fuel rail side.
3. Assemble special tool, M0998709 and special tool M0998742

pic 2

4. Place a suitable O-ring or gasket on the assembled special tools MD998709 and MD998742 and install the fuel pressure gauge.

pic 3

5. Install special tool MD998742/MD995709 (created in steps 3 and 4), between the fuel rail and the high-pressure fuel hose.

pic 4

6. Connect scan tool MB991502 to the data link connector.
7. Use the Actuator Test 25 to drive the fuel pump. Check that there is no fuel leaking from any section when the fuel pump is operating.
8. Stop the fuel pump.
9. Start the engine and run at idle.
10. Measure fuel pressure while the engine is running at idle.

Standard Value: Approximately 270 kPa (38 psi) at curb idle

pic 5

11. Disconnect the vacuum hose (blue stripe) from the air intake fitting and then plug the nipple.
Measure the fuel pressure in this condition.

Standard value: 330 - 350 kPa (47 - 50 psi) at curb idle

12. Check to see that fuel pressure at idle does not drop even after the engine has been raced several times.
13. Racing the engine repeatedly, hold the fuel return hose lightly with fingers to feel that fuel pressure is present in the return hose.

NOTE: If the fuel flow rate is low there will be no fuel pressure in the return hose.

pic 6

14. If any of fuel pressure measured in steps 10 to 13 is out of specification, troubleshoot and repair according to the table above.

pic 7

15. Stop the engine and observe fuel pressure gauge reading. Normal if the reading does not drop within two minutes. If it does, observe the rate of drop and troubleshoot and repair according to the table above. Start, then stop the engine.
(1)Squeeze the fuel return line closed to confirm leak-down occurs from defective fuel pressure regulator.
(2)Squeeze the fuel supply line closed to confirm leak-down occurs from defective fuel pump check valve.
(3)If pressure continues to drop with both fuel lines squeezed closed, injector(s) are leaking.
16. Release residual pressure from the fuel pipe line.

WARNING: Cover the hose connection with shop towels to prevent splash of fuel that could be caused by some residual pressure in the fuel pipe line.

pic 8

17. Remove the fuel pressure gauge and special tools MD998709 and MD998742 from the fuel rail.
18. Replace the O-ring at the end of the high-pressure fuel hose with a new one.
19. Fit the high-pressure fuel hose into the fuel rail and tighten the bolts to specified torque.

Tightening torque: 5 N.m (3.6 ft-lb)

20. Check for fuel leaks.
(1)Use scan tool MB991502 to operate the fuel pump.
(2)Check the fuel line for leaks, repair as needed.
21. Disconnect scan tool MB991502.

____________________

Let me know what you find.

Joe

Hi,

Okay, but based on your description, I still feel it's fuel related. When it wouldn't start and you sprayed starting fluid in the filter, you provided fuel to the engine which started it but then it stalled again when the fluid burned off.

Have you checked the fuel pump relay? I attached a picture of its location. Here is a link that explains how to test one:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Also, check the pump ground which could be weak. See picture 2.

Let me know what you find.

Joe

Sounds good. Let me know what you find.

Joe